Do speaker wires degrade over time ?

There is a life expectancy for everything, including cables. It may be thousands of years, but eventually they will degrade down to nearly nothing...

Entropy - the universe tends toward maximum disorder. IOW, everything falls apart.

Well if it was equipment, I might consider it, but It's cabling and it's 30 year old technology!! If you can get it in the price range of free to $25, I would do it.

It is a run of transparent audio for around $225.00

The biggest problem is surface oxydation of the copper within the wires (if the insulation is allowing/ or causing! the wire to have a damaged surface. The other thing is the insulation may be breaking down, and not providing anough insulating. (I had some AudioQuest Midnight wire that the insulation started to get soft, and the wire really was ruined.)
I would NEVER pay good money for wire that old. period. If you got it for nearly free, say ten bucks.. but to pay $225 for it is crazy.
For $225 you can buy brand new Kimber 8TC... So that price of $225. is just nuts i'm afaid.